VANCOUVER - There's been a series of entanglements and collisions involving humpback whales in British Columbia waters in recent weeks as numbers of the mammals surge, but the circumstances of the latest crash were "exceedingly rare," said the head of the Pacific Whale Watch Association.

That's because the boat suspected to have struck a humpback found dead in Howe Sound was a whale-watching vessel, operated by the B.C.-based Prince of Whales tour company.

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